Metallization of Alumina Ceramic Substrates by Electroless-Plated Films

Abstract

The mechanism of adhesion between electroless-plated films and polished alumina ceramic substrates was investigated. The adhesion strength of the electroless Cu and Ni-P films for etched alumina substrate, Ra 0.04μm, was 1.4kgmm^-2 and 2.7kgmm^-2, respectively. It was found that the difference in the morphology between these films at the initial deposition state causes the difference in their adhesion strength. The Cu deposit was rough and granular at the initial state, but the very thin (0.05μm) Ni-P film underlayer film changed the morphology of the Cu deposit into fine-grainy condition, and improved the adhesion strength of the Cu film drastically up to 2.7kgmm^-2. It is concluded that the initial deposition condition is one of the most important factors in controlling the adhesion strength between Cu films and alumina substrates.